1. Field of the Invention
The present invention relates to a socket connector, and more particularly to a socket connector having a vented pick up cap mounted thereon capable of efficiently protecting the contacts in the socket connector.
2. Description of Related Art
An IC package, such as a CPU (Central Processing Unit), is generally coupled with a system via a socket connector mounted on a PCB (Printed Circuit Board). A typical socket connector is disclosed by U.S. Pat. No. 7,140,890 issued to Ted Ju on, on Nov. 28, 2006. Referring to FIG. 2 to FIG. 4 of this patent, the socket connector includes a socket body and a pick up cap mounted upon the socket body. A plurality of contacts are received within the socket body, and generally a corresponding number of solder ball are attached to the bottom of the contacts, respectively. The pick up cap serves two purposes: 1) It protects the contacts from being damaged and dust, and 2) It provides a comparably flat surface required for a pick-and-place robot to pick up the socket connector with a vacuum nozzle. The socket is first placed onto a PCB by the robot and then soldered onto the PCB in a reflow environment under a special temperature, so that the solder balls melt and joint with the soldering paste on the PCB, and are then cooled and solidified after the reflow soldering process. The socket connector is therefore soldered and positioned onto the PCB. In fact, during reflowing process, the periphery section of the housing is heated more quickly than the sheltered central portion of the housing so that the housing tends to easily warp upward away from the PCB and lift the periphery solder balls out of the solder paste on the PCB. So the soldering defect is resulted.
U.S. Pat. No. 6,875,022 issued to Hao-Yun Ma, on Apr. 5, 2005 discloses a socket connector that is able to overcome the defect discussed above. As shown in FIG. 2-FIG. 5 of Ma, the socket connector has a pick up cap mounted upon a socket body and having two cutouts thereon. During reflowing process, the cutout servers as a path allowing the heat to reach to an upper surface of the housing so as to provide the socket connector with a relatively even thermal environment. The pick up cap according to Ma is great for improving soldering quality. However, it could be more effective for protecting the contacts from potential mechanical damage and contamination if certain features are included and modified.
In view of the above, an improved socket connector is desired that is able to efficiently protect the contacts thereof and simultaneously ensure fine soldering quality is desired.